Tropical rain forests in Borneo Island support amazing amount of biomass with fast turnover of phytoproduction and tree species diversity. This type of forest ecosystem is experiencing the immense human impact, responding quickly to changing climate and land use. It is thus particularly important to monitor the changing process of tropical rain forests along the purpose of projecting ecosystem change in response to climatic change. This program monitored typical foothill dipterocarp mixed forest, lowland heath forest, and lowland freshwater peat swamp forest in West and Central Kalimantan, and Brunei. Demographic and ecosystem processes were intensively monitored in permanent research plots set across these forest types.Based on demographic data of mixed dipterocarp forest in Serimbu, West Kalimantan, we proposed a simulation model describing forest structure dynamics in gap-mosaic landscape, that satisfactorily projected the present landscape architecture of forests. Similar model was
… More applied to describe different forest types. The monitored heath forest in Lahei, Central Kalimantan, showed that dense bole-class layer of the forest compared to mixed dipetrocarp forest was not due to the depression of growth at this stage but high upgrowth and rapid recruitment, because the depression by poor nutrient was only for canopy stage trees. As a result, the biomass turnover(biomass divided by net primary production)was just the same between heath forest and mixed dipterocarp forest, which has two times larger biomass. Repeated recensuses of tree trunk girth efficiently recorded temporary variation of production. Reduction of biomass increment after 1997 El Nino was particularly obvious. Further continuation will give us essential information to relate forest ecosystem functioning and environmental change.また,すでに1992年来設定している西カリマンタン州ランダック川中流部のスリンブの混交フタバガキ林の追跡データから,森林のギャップ動態・サイズ分布動態を再現するモデルを提出した.さらに,本研究では,マレーシア領サバ州のキナバル山の植生と,サラワク州での予備調査,またブルネイ領のタセック・マリンブン保護地における泥炭湿地林の調査区設営など,ボルネオ島の森林タイプを広くカバーする野外調査を実施した.これら永久調査区の同時追跡データによって,きわめて急速に進行している森林の人為的な衰退が,ボルネオ熱帯林のポテンシャルに及ぼしつつある影響が,今回のセンサスと今後のその継続によって的確に把握できるものと考えている. Less